1. Field of the Invention
The present invention relates to a method and system for remote process control and monitoring of applications in a wireless network architecture.
2. Description of Related Art
In process control applications, conventional wired RS232 connections over short distances is a preferred method for communication and control because of the very high reliability, accuracy and ease of such connections. Wired communications, such as RS232, are highly reliable and in addition RS232 connections guarantee the deliver of the data that is sent.
Commercial Wireless Packet Data Networks serve multiple applications, such as email, file transfer, and the like and are designed to perform well over a wide geographical area. Most of these applications can tolerate some minor inaccuracies once in a while. The applications are also tolerant of delays in the receipt of data. However, process control and process monitoring applications cannot tolerate inaccuracies and the delay in data receipt has to meet stringent requirements as well. For these reasons, Wireless Packet Data Networks have not been widely accepted in these applications.
U.S. Pat. No. 6,678,255 describes techniques for transmitting process control using a wireless data interface system for fixed point-to-point communication over geographically separated areas, this patent is hereby incorporated by reference in its entirety into this application. Data is collected by a remote monitoring device and transmitted to a first Cellular Digital Packet (“CDPD”) modem via a RS232 interface. The CPDP modem transmits a signal to a second CDPD modem for initiating communications. The second CDPD modem returns a signal indicating the status of the interface. Data transmission is initiated when the status of both serial data interfaces is established. The data to be transmitted is concatenated to a signaling packet on the initiating side and the packet is transmitted. All messages that are received are assumed to be received without error. There is no methodology for determining if the message has residual errors. The results from this technique is not quantifiable regarding accuracy and reliability.
It is desirable to provide a method and system to enable transmission of data over Wireless Packet Data Networks in geographically separated areas with quantifiable reliability and accuracy as comparable to wired communications in general and superior to wired communications in specific circumstances in which information messages can be transmitted by a high accuracy protocol and signaling messages can be separately transmitted by a fault tolerant protocol.